As the technology advances, electronic devices such as desktop computers, laptop computers and servers have played an important role in the daily life. Each electronic device is provided with a circuit board (or a motherboard) that is fixed to a housing of the electronic device. Various ways for fixing the circuit board to the electronic device are available and cause different effects on the circuit board.
FIG. 1A is a top view of a conventional circuit board 12 mounted on a housing 13 of an electronic device, and FIG. 1B is a front view of the structure shown in FIG. 1A. As shown in FIGS. 1A and 1B, the housing 13 of the electronic device is formed with a plurality of carrier pads 131 thereon, wherein each of the carrier pads 131 has a blind hole 1311. The circuit board 12 has a plurality of openings 121 corresponding to the blind holes 1311 of the carrier pads 131 and is placed on the carrier pads 131. The circuit board 12 is fixed to the housing 13 of the electronic device by a plurality of coupling members 11 such as screws inserted into the openings 121 and the blind holes 1311.
To fix the above circuit board 12 to the housing 13 of the electronic device needs a screwdriver or a similar tool to screw the coupling members 11, which is rather troublesome and time-consuming to implement. If a force for screwing the coupling members 11 is not properly controlled, the circuit board 12 may be damaged by the coupling members 11. Moreover, since the coupling members 11 are often made of a metallic material having electrical conductivity, they may cause signal interference to the circuit board 12, thereby adversely affecting the performance of the circuit board 12.
Thus, Taiwanese Patent No. 00510512 proposes a computer with a screw-free motherboard. Referring to FIG. 2A, the computer with a screw-free motherboard comprises a housing 23, a block 24 and a pillar 21 that are formed on the housing 23, and a circuit board 22. When mounting the circuit board 22 on the housing 23, a wide portion 2211 of a mounting hole 221 of the circuit board 22 is put around a protruding portion 211 of the pillar 21 to reach a neck portion 212 of the pillar 21, and then the circuit board 22 is moved in a direction indicated by arrow A (as show in FIG. 2B) to allow the neck portion 212 of the pillar 21 to be engaged with a narrow portion 2212 of the mounting hole 221 of the circuit board 22, such that a terminal 222 of the circuit board 22 is blocked by the block 24 on the housing 23, so as to firmly fix the circuit board 22 on the housing 23, without using any screw to position the circuit board 22.
However, the above computer with a screw-free motherboard requires provision of the block 24 on the housing 23. The block 24 is an elastic hollow structure and can be deformed if being pressed by the circuit board 22, such that the positioning effect of the circuit board 22 is affected by the elastic deformation of the block 24. Moreover, the above design requires formation of the mounting hole 221 having the wide portion 2211 and the narrow portion 2212 for the circuit board 22, thereby undesirably increasing the fabrication cost.
Therefore, the problem to be solved here is to provide a circuit board fixer structure to overcome the foregoing drawbacks of the prior art.